Nurse staffing and post-surgical complications using the present on admission indicator.

We evaluated the relationship between registered nurse (RN) staffing and six post-surgical complications: pneumonia, septicemia, urinary tract infections, thrombophlebitis, fluid overload, and decubitus ulcers, in a dataset that contained the present on admission (POA) indicator. We analyzed a longitudinal panel of 283 acute care hospitals in California from 1996 to 2001. Using an adaptation of the Quality Health Outcomes Model, we found no statistically significant relationships between RN staffing and the complications. In addition, the signs of the relationships were opposite to those expected. That is, as staffing increased, so did some of the complications. We discuss potential reasons for these anomalous results, including the possibility that increases in RN staffing may result in earlier detection of complications. Other explanations include issues with risk adjustment, the lack of nurse level variables in the model, and issues with the POA indicator itself.